1. Field of the Invention
The present invention relates to a motor and a generator of which the armature is wound by a coil and also relates to a method thereof.
2. Description of the Related Art
A rotating electrical unit has been conventionally and widely used in various fields. Here, the rotating electrical unit includes a motor and a generator. The use of the rotating electrical unit is not limited but here it is used as, for example, a motor for driving the compressor of an air conditioner, a motor for running an electric vehicle (including a hybrid car), a generator mounted on a car, etc.
The rotating electrical unit is generally provided with a coil for generating a magnetic field (in the case of a generator, a coil for generating electromotive force in accordance with the change of a flux). The following method is well known as a method of forming a conventional wire.
For example, in a rotating electrical unit described in patent document 1, a coil is formed by repeatedly winding a conductor wire around the slot of a stator. This stator includes a plurality of stator pieces and these stator pieces are combined after a coil is formed for each stator piece. Therefore, this method has a merit such that a winding operation becomes easier in comparison with a method of winding a conductor wire around the slot provided on a cylindrical stator core.
In addition, in patent document 2, a technology called insert method is described. In the insert method, a coil is produced in advance by winding one conductor wire several times around a ring-shaped frame, etc. and this ring-shaped coil is inserted into the slot corresponding to a stator core using a device called an inserter. According to this insert method, since a conductor wire need not be wound directly around a slot of the stator core, the operation of forming a coil becomes easier.
[Patent document 1]
Japanese patent laid-open application publication 9-191588 (FIGS. 1 and 2, paragraphs 0023 to 0030).
[Patent document 2]
Japanese patent laid-open application publication 58-33945 (pages 1 and 2).
In a case where a coil is formed by winding a conductor wire directly around a slot provided at a stator core (especially, in a case where a slot is provided on an inner circumference side of a cylindrical stator core), the labor for a winding operation increases. In the method described in patent document 1, this problem is alleviated. According to the method described in patent document 1, however, it is interpreted that the configuration of a stator core is complicated and the coil is limited to a concentrated winding.
In the insert method described in the patent document 2, an inserter itself is a relatively large-scale and also expensive device. Especially in a case where a stator core has a long cylindrical shape, a coil can be hardly inserted into the corresponding slot.